The present invention is directed to an explosive powder charge operated setting tool having a housing including means located within and extending in the axial direction from the housing for effecting contact pressure with a structural component into which a fastening element is to be driven. A piston guide is located within the housing in contact with and behind the means so that both the means and the piston guide are axially displaceable when pressed against the structural component. Upon axial displacement of the means and the piston guide a device including a firing pin is displaced into the ready-to-fire position. The housing has a magazine extending transversely of the axial direction of the piston guide and aligned with a passage in the housing, so that fastening elements in the magazine each secured in a guide member and connected together in a belt-like manner can be inserted into the setting tool.
An explosive powder charge operated setting tool with a transversely extending magazine for fastening element secured in guide bushes connected in a belt-like manner is known from DE-A-36 06 514. In this known setting tool containing the magazine the same problem that existed in individually fired tools must be solved, that is, the tool can be placed in the operating condition for firing explosive powder charges only if the tool is pressed against a structural component into which the fastening elements are to be driven. This feature is the only way for avoiding accidents that could result in injuring personnel.
To assure this operational feature the known setting tools have a firing mechanism for the explosive powder charges and it is placed in the cocked or ready-to-fire position only if the setting tool is pressed against a structural component. Accordingly, a device for placing the firing pin in the ready-to-fire position is provided cooperating with the axially displaceable piston guide. The piston guide is displaceable within the housing containing the magazine. The housing can be constructed in several parts to achieve additional operational features.
An axially displaceable contact pressure probe cooperates with the axially displaceable piston guide and projects beyond the front end face of the setting tool when it is not pressed against a structural component. When the setting tool is pressed against a structural component, the contact pressure probe is displaced rearwardly in the housing opposite to the setting direction and a similar displacement of the piston guide is effected and the placement of the firing pin in the ready-to-fire position is achieved. In the ready-to-fire position, the setting tool is ready to operate by igniting the explosive powder charge. As a result, the above-mentioned setting tool satisfies the requirements for security or safety in connection with pressing the setting tool against the structural component. The security feature regarding feeding the fastener element into the guide is not completely assured. Since the housing has an opening or through-passage for introducing the fastening elements from the transversely extending magazine into the housing and has a constant inside projection in the various positions of the setting tool, there is the danger, because of the feeding mechanism for the fastening elements, that the elements are driven to such an extent into the housing that the next following fastening element is in a position to be contacted by the driving piston. While the fastening element to be driven is in proper position, the next following fastening element is located in the housing in such a position that it tends to cause an operational malfunction. In an extreme case this next following fastening element can form a passage for itself and exit from the setting tool, causing destruction of parts of the housing wall or of the magazine.